The present invention is directed generally to a closure for a container. More specifically, the present invention relates to a ball and socket closure for use with specimen containers for biological and non-biological samples.
Medical specimens, for example, biological and non-biological fluids, solids and semi-solids, are routinely collected and analyzed in clinical situations for various purposes. In particular, biological fluids such as blood, urine, and the like are typically collected in a specimen collection container which is in the shape of an open-ended tube. Such a tube is generally in the form of an elongate cylindrical member having one end open and an opposing end permanently closed by an integral semi-spherical portion, with the tube defining an interior which collects and holds the specimen.
After a biological sample has been drawn and/or collected in the tube, the tube with the sample is typically transported to a clinical testing laboratory for analysis. For example, blood samples may undergo routine chemistry, hormone, immunoassay or special chemical testing. In order to conduct such testing, the sample is normally transferred from the primary tube in which the sample was collected into one or more secondary tubes for testing and analysis, oftentimes to effect simultaneous testing in two or more different areas. In order to minimize contamination, evaporation and spilling during transportation, analysis and storage, it is important to maintain the open end of the tube with a closure.
The open end of a specimen container is typically sealed by a resilient cap, a removable rubber stopper, or plastic film during transport and analysis. Such closures provide means for sealing the open end of the tube, but are not capable of being efficiently removed, stored and replaced without causing contamination and with the use of one hand, as is often desired in clinical environments. Furthermore, when using analytical testing equipment for testing biological samples, it is typically necessary to maintain the samples in an open container to allow a probe from the testing equipment to be inserted into the container. In view of these needs, it is desirable to have a closure that can be easily and repeatedly opened and closed for manual or automated access.
One particularly useful type of closure for containers is a ball and socket type closure. While a number of ball and socket type closures for various containers are known, none are entirely effective for use in specimen collection containers, where an adequate seal is essential.
Further, it is often desirable to provide closures for containers with a locking mechanism. For example, U.S. Pat. No. 2,032,776 to Van Ness describes a closure for a dispensing container including a valve ball having a bore which sits within a curved boss on a resilient disc having an opening into the container. In one embodiment, the valve ball may include a projection of similar size to the opening of the resilient disc such that, when the ball is in the closed position, the projection sits within the opening of the resilient disc to lock the ball in place.
Still further, U.S. Pat. No. 4,181,246 to Norris discloses a closure for a collapsible tube which incorporates a stationary ball attached to the open end of the tube and including a bore therethrough and a moveable cap covering the stationary ball. The cap includes openings therein which can be aligned with the bore of the stationary ball upon movement of the cap. In one specific embodiment of this invention, the cap includes a detent which snaps into a recess in the ball for providing a locking mechanism for the closure.
Accordingly, it is desirable to provide a closure for a specimen collection container which can be easily and repeatedly opened and closed and which can effectively provide an adequate seal.
It is an object of the present invention to provide a closure for a specimen collection container which can be easily manufactured.
It is a further object of the present invention to provide a closure capable of being easily and repeatedly opened and closed.
It is yet a further object of the present invention to provide a closure for a specimen collection container which can be repeatedly opened and closed while maintaining an adequate seal.
In the efficient attainment of these and other objects, the present invention provides a closure for sealing the open end of a specimen collection container from the environment. The closure includes a socket mountable on the open end of the collection container for enclosing an interior region of the collection container. The socket includes a ball receiving internal surface having a protrusion thereon. The closure further includes a generally spherical-shaped ball mounted within the socket and at least partially enclosed by the socket. The ball is capable of rotative movement within the socket between an open position and a closed position. The ball includes an external surface capable of interference engagement with the protrusion of the socket upon rotative movement of the ball between the open position and the closed position.
The protrusion may include a rib along the ball receiving internal surface, or may include a dimple on the ball receiving internal surface.
Desirably, the ball includes an environment-contacting surface which is exposed to an external environment when the ball is in a closed position. The environment-contacting surface is preferably recessed with respect to the general spherical-shape of the ball to define a perimetrical edge therearound. Further, the socket preferably includes an open upper end permitting exposure of the environment-contacting surface to the external environment when the ball is in a closed position. More preferably, the protrusion is located on the ball receiving internal surface of socket at a position adjacent the open upper end of the socket. As such, the perimetrical edge of the ball and the protrusion of the socket are capable of interference engagement therebetween.
In a further embodiment of the present invention, a closure for sealing an open end of a specimen collection container from the environment is provided which includes a socket mountable on the open end of the collection container for enclosing an interior region of the collection container. The socket includes a ball receiving internal surface having a protrusion thereon. The closure further includes a generally spherical-shaped ball mounted within the socket which is capable of rotative movement between an open position and a closed position. The ball includes an environment-contacting surface, an opposed specimen-contacting surface and a passageway extending therethrough. The passageway is aligned with the open end of the collection container when the ball is in an open position, while the environment-contacting surface is exposed to an external environment and the specimen-contacting surface is exposed to the interior region of the collection container when the ball is in a closed position. The environment-contacting surface of the ball is recessed with respect to the general spherical-shape of the ball to define a perimetrical edge. As such, the environment-contacting surface does not contact the interior surface of the socket when the ball is in the open position, and rotative movement of the ball within the socket between an open position and a closed position causes interference engagement between the perimetrical edge of the environment-contacting surface and the protrusion of the internal surface of the socket.